This summer, perhaps while you were lounging around the pool in the blistering heat, the blogosphere was buzzing about data taken at the Large Hadron Collider1 at CERN. The buzz reached a crescendo in the first week of July when both Fermilab and CERN announced the results of their searches for the Higgs boson. Hard data confronted a theory nearly half a century old and the theory survived.

The International System of Units (SI) is a coherent system based originally on measurements of properties of material objects. In more recent times, the adopted definitions depend on setting values of universal constants wherever possible. The last remaining humanmade material object on which a standard is based is a platinum-iridium kilogram located in Sèvres, France. The International Bureau of Weights and Measures is considering replacing this physical object as the standard and tying all base units to physical constants that are fixed. The reasons will be explicated in this paper.

One of the very popular demonstrations used in introductory physics courses to illustrate Lenz's law is the “slowly falling magnet.” In its simplest version it requires only a powerful cylindrical magnet and a metal tube, typically of copper or aluminum. When dropped in the tube the magnet takes significantly longer to reach the other end than a geometrically similar but nonmagnetic object. This demonstration has been adapted for use in large classes using a camera to monitor the magnet as it approaches the end of the tube.1 Small versions that can be used for hands-on experiments also have been developed2 or are available commercially.3 This classical demonstration in its various forms almost never fails to impress first-time viewers.

In this paper we investigate the speed of sound in air as a function of temperature using a simple and inexpensive apparatus. For this experiment it is essential that the appropriate end corrections be taken into account. In a recent paper1 the end corrections for 2-in i.d. (5.04-cm) PVC pipes open at both ends were investigated. The air column resonance was excited using a paddle as in Blue Man Group® pipes.2 The “open end” end correction is given by 0.6133r in accordance with recent experiments3 and detailed theoretical calculations.4 This correction amounted to 1.56 cm for the 2-in PVC pipe used. However, the paddle end correction was found to be influenced by the transient position of the paddle during the excitation process. The paddle end correction was found to be 1.94 cm.

The Fukushima Daiichi nuclear accident is a topic of current media and public interest. It provides a means to motivate students to understand the fission process and the barriers that have been designed to prevent the release of fission products to the environment following a major nuclear powerreactor accident. The Fukushima Daiichi accident further encourages a discussion of the effect of fission products upon the environment, including the resulting contamination of air, water,soil, animals, fish, milk, and crops. Accident-generated radiation levels that caused the evacuation of people 20–30 km from the facility further serve to foster student interest and desire to understand the science associated with the Fukushima Daiichi accident.

Almost all introductory physics classes will, at some point, include springs and elastic forces. When studying such topics, it is interesting to consider the spring system shown in Fig. 1. In this system, two identical springs are arranged with the top of one spring anchored to the ceiling and the bottom of the second spring attached to a hanging weight. The two springs are then connected by a “middle” string, c. There are two other strings that are not tensioned (strings d and b), one connecting the ceiling and the bottom spring, and the other connecting to the hanging weight and the top spring. As indicated in Fig. 1, these two “support” strings have some slack in them.

Physics Education Research is a form of social science research in that it uses human subjects. As physicists we need to be aware of the ethical and legal ramifications of performing this research, taking into account the fundamental differences between working with substances and working with people. For several decades, the federal government has regulated research involving human subjects. With current procedures, a proposal soliciting federal funds for a research project involving human subjects will be flagged by the applicants institution and checked for compliance with appropriate regulations. However, there is a large body of Physics Education Research that is not federally funded and thus may not be flagged. Nevertheless, there are ethical standards that apply to this research. This paper outlines the preliminary considerations for conducting such research.

Many of us have played the PC Solitaire game that comes as standard software in many computers. Although I am not a great player, occasionally I win a game or two. The game celebrates my accomplishment by pushing the cards forward, one at a time, falling gracefully in what appears to look like a parabolic path in a drag-free environment. One day, as I was watching this progression, I asked myself what is the downward acceleration of the playing cards. Could the game programmer have used a realistic value of Earth's acceleration due to gravity? It occurred to me that this could be an excellent open-inquiry activity for high school or introductory college physics students!

An interesting, quick, and inexpensive lab that we do with our students is to tape one end of a string just less than halfway around the back side of a uniform solid cylinder m1 and attach the other end of the string to a mass m2 that is below a pulley (Fig. 1). Data can be collected using either an Ultra Pulley (Fig. 2) or a motion detector with a protective cage designed to stop the falling mass (Fig. 3). We found that each measuring device worked equally well. When experimenting, let m2 hang freely and release the cylinder. The mass m2 is allowed to fall a defined distance h. Note that many motion detectors do not measure accurately within 15 cm of the detector.

I spent the 1972“73 academic year on sabbatical leave at the Kingston, Jamaica, campus of the University of the West Indies. One of my duties was to give Saturday morning enrichment lectures to the students, and the best one was on suspension bridges. The demonstration lecture then went on tour to high schools in Jamaica and the Cayman Islands. During the course of the talk, I “built ”the suspension bridge in Fig. 1; this picture was published in the January 1974 issue of The Physics Teacher.1

To date, this column has presented videos to show in class, Don Mathieson from Tulsa Community College suggested that YouTube could be used in another fashion. In Don's experience, his students are not always prepared for the mathematic rigor of his course. Even at the high school level, math can be a barrier for physics students. Walid Shihabi, a colleague of Don's, decided to compile a list of YouTube videos that his students could watch to relearn basic mathematics. I thought this sounded like a fantastic idea and a great service to the students. Walid graciously agreed to share his list and I have reproduced a large portion of it below.